sue thompson is live at the scene on bridgeport court. >> reporter: good morning. investigators will be back out here later today to try and determine or at least work towards what caused this fatal fire over the weekend. some residents tell abc7 news that the fire alarm never went off. that fatal fire tore through an upper apartment at 3700 bridgeport court saturday night. many say they had to run for their lives to escape the fast flames and intense smoke. sadly, 4-year-old and her grandparents died when they were trapped in a back bedroom because of the flames. her mom said she barely made it out alive and she woke to flames in a bedroom and the fire alarm never went off. some 52 people have been displaced because of this fire. they will not be able to come back home until power is restored to the building. red cross has stepped in to try and provide shelter. the grandparents that perished in the fire we are told they lived in the apartment for more than 20 years, and their daughter said she desperately tried to save them saturday night and her little girl, but